The present invention relates to generators and, more particularly, to a field winding enclosure having a non-circular shape.
In a conventional generator having a rotor and a stator, the rotor is provided with field windings that excite the generator while receiving a current from an exciting current source. The stator is provided with armature windings from which electrical power is output. Containment of the rotor field windings can be achieved by enclosing the assembly in an enclosure, which eliminates the need for rotor wedges, rotor teeth and retaining rings.
Reluctance is the magnetic analog to resistance in an electric circuit. The reluctance of a magnetic circuit in an electric power generator is most sensitive to the size in the gap between the generator rotor and stator along the rotor pole direction (d-axis), where most of the flux transfer takes place, and is least sensitive 90.degree. away (along the q-axis). Centrifugal loading, on the other hand, is primarily distributed along the q-axis.